Leash knots drop when broken in creative mode

The Bug

When using left-click to break a leash knot attached to a mob and fence in creative mode drops the item. Right clicking it to destroy it doesn't do this.

Steps to Reproduce

• Summon a pig and place down a fence.
• Obtain a lead, and use it to leash the pig to the fence.
• Ensure that you're in creative mode, if not already.
• Use the Attack/Destroy button (left-click by default) on the leash knot.

Observed Behavior

Leash knots are dropped when broken in creative mode.

Expected Behavior

Leash knots would not be dropped when broken in creative mode.